html {
    height: 100%;
}

body {
    font-family: 'Noto Sans TC', sans-serif;
    background-image: url(../images/poster.jpg);
    background-repeat: no-repeat;
    background-attachment: fixed;
    background-position: center;
    background-size: cover;
    .link {
        position: absolute;
        top: 64%;
        left: 24%;
        .btn-primary {
            padding: 15px 20px;
            font-size: 16px;
            border-radius: 30px;
            background: -webkit-linear-gradient(top right, #e80808, #0400ff);
            background: -o-linear-gradient(top right, #e80808, #0400ff);
            background: -moz-linear-gradient(top right, #e80808, #0400ff);
            background: linear-gradient(top right, #e80808, #0400ff);
            @media screen and (min-width: 340px) {
                font-size: 17px;
            }
            @media screen and (min-width: 340px) {
                font-size: 18px;
            }
            @media screen and (min-width: 360px) {
                font-size: 19px;
            }
            @media screen and (min-width: 375px) {
                font-size: 20px;
            }
            @media screen and (min-width: 400px) {
                font-size: 21px;
            }
            @media screen and (min-width: 414px) {
                font-size: 23px;
            }
            @media screen and (min-width: 480px) {
                font-size: 27px;
            }
            
        }
    }
}